Power cutter

ABSTRACT

A power cutter for cutting deformable material and including a frame which has upper and lower jaws for receiving the material to be cut. The lower jaw includes a recess within which a cutting disc is rotatable by an associated power drive. The upper jaw is formed with depending cheek portions located on opposite sides of the cutter means to define side passages. The cheek portions extend forwardly of the cutter disc in overlying relation to a projecting guide shoe portion of the lower jaw to thereby define a frontal passage ahead of the cutting disc. The access openings to the frontal passage and the side passages are made sufficiently large that the material to be cut can pass therethrough, but sufficiently small that a person cannot inadvertently insert his finger and become cut by the cutting disc. The recess within which the cutter is rotatable and which is defined by the frame upper and lower jaws is of inverted Ushape to make accidental insertion of a finger even more difficult, the material to be cut deforming into a corresponding U-shape for entry and cutting thereof.

United States Patent Cunningham [54] POWER CUTTER Frank W. Cunningham, 23151 Doris Way, Torrance, Calif. 90505 22 Filed: Sept. 28, 1970 [2i] Appl.No.: 76,044

[72] Inventor:

Primary Examiner-Theron E. Condon Assistant Examiner.l. C. Peters AttorneyFulwider, Patton, Rieber, Lee & Utecht ABSTRACT A power cutter for cutting deformable material and including a frame which has upper and lower jaws for receiving the material to be cut. The lower jaw includes a recess within which a cutting disc is rotatable by an associated power drive.

.The upper jaw is formed with depending cheek portions located on opposite sides of the cutter means to define side passages. The cheek portions extend forwardly of the cutter disc in overlying relation to a projecting guide shoe portion of the lower jaw to thereby define a frontal passage ahead of the cutting disc. The access openings to the frontal passage and the side passages are made sufficiently large that the material to be cut can pass therethrough, but sufficiently small that a person cannot inadvertently insert his finger and become cut by the cutting disc. The recess within which the cutter is rotatable and which is defined by the frame upper and lower jaws is of inverted U-shape to make accidental insertion of a finger even more difiicult, the material to be cut deforming into a corresponding U-shape for entry and cutting thereof.

6 Claims, 6 Drawing Figures POWER CUTTER CROSS REFERENCE TO RELATED APPLICATION This application is related generally to a manually operable device which is the subject of my US. Pat. No. 3,365,798, issued Jan. 30, 1968, and entitled DEVICE FOR CU'ITING SOFT WRAPPINGS". However, the present power operated cutter has broader utility, and is characterized by a different shielding or guarding arrangement to protect the user from injury by the cutter means.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power cutter for cutting deformable material, and is particularly adapted for cutting soft wrappings or the like.

2. Description of the Prior Art Heretofore the cutting of deformable material such as the soft wrappings utilized in medical applications involved a degree of risk to the user or patient. Where the cutter was manually operated the procedure was relatively slow and deliberate, and adequate control could be exercised to keep the patient from having his fingers caught between the cutting edges, and to prevent cutting of the patient in the area from which the soft wrappings were to be removed. However, the slowness and laborious nature of manual cutting devices is itself a disadvantage and power cutters are being utilized more frequently.

Presently available power cutters for cutting deformable material such as soft wrappings lack a reliable means for guarding or shielding the cutting means from the patient and the operator. Most of the power cutters that provide some form of guard utilize a movable or pivotable element which is moved out of the way by the material to be cut. That is, as relative movement occurs between the cutter and the material to be cut, the material passing to the cutter moves the pivotable guard element out of the way to allow the material to pass into contact with the cutter. Unfortunately, the guard element can also be pivoted out of the way by a persons finger. Some presently available power cutters do not have any guard at all, so that great caution must be exercised by both the operator and the patient to avoid injury during the cutting operation. Insofar as applicant is aware there is no power cutter in the prior art which provides the desired cutting action in such a way that material can be pressed into contact with the cutting means without undesirably affording a similar opportunity for a person to insert his finger inadvertently and thereby cut himself.

SUMMARY OF THE INVENTION According to the present invention, a power cutter is provided which includes upper and lower jaws configured in such a manner that the entry passages to the cutting area are too small for a person to accidentally insert his finger, while are yet large enough that material to be cut can pass into the cutting area. In addition, the cutting area is U-shape to further shield the cutter, the material being deformed to pass into the cutting area. The direction of rotation of the cutter is preferably toward the direction of the entering material to prevent the material from being pulled inwardly by the rotating cutter. The components of the cutter are assembled in a manner enabling ready disassembly for sharpening or replacement when necessary. Preferably, the cutter is driven by an integral drive means forming a handle, and different embodiments are provided to permit cutting along an axis aligned with or at right angles to the axis of the handle. The cutter is relatively inexpensive to manufacture, easy to operate, and characterized by a long service life. I

, Other objects and features of the invention will become apparent from consideration of the following description taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a power cutter according to the present invention;

FIG. 2 is an enlarged end elevational view of the cutter of FIG. 1;

FIG. 3 is an enlarged view taken along the line 3-3 of FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, and particularly to FIGS. 1-5, there is illustrated a power cutter for cutting deformable material such as the soft wrappings or bandages utilized in medical applications. A particular medical use would be the cutting of the soft underwrappings in a plaster cast for a broken arm or the like. In such a use. a suitable slot is first formed in the cast by a saw. The power cutter is equally useful in cutting other types of soft materials which can be deformed for entry into the guarded cutting area. In this regard, the present cutter is particularly adapted to protect persons around it from being cut or injured. For this purpose fixed or non-pivotable structure is provided which guards all openings to the cutting area. The structure provides openings sufficiently large for the material to pass into the cutting area, but sufficiently small that a patient, user, or operator cannot inadvertently insert his finger and injure himself.

The power cutter includes an elongated body or handle portion 10 of generally cylindrical configuration which serves not only as a handle for grasping the cutter, but also as a housing for enclosing a conventional electric drive motor (not shown). The motor is turned on and off by a usual switch 12 on the end of the handle, and is connected to a source of power by a cord 14. Opposite the switch 12, the handle portion 10 is connected to one end of a hollow cylindrical, slightly tapered intermediate member 16. The other end of the member 16 is threadably mounted to an annular collar 18, which forms part of a cutter assembly or head 20. The cutter head 20 serves as a mounting meansfor a cutting means in the form of a cutter disc 24.

A drive shaft 22 driven by the drive motor extends from the handle portion 10, through the intermediate member 16, and

, lar cap 26 which has a circular recess to receive the portion of the shaft 22 which protrudes through the central mounting hole in the disc 24. The cap 26 is held in position by a machine screw 28 which extends through an opening in the cap 26 and is threaded into a threaded opening in the end of the drive shaft 22. Removal of the cutter disc 24 from the shaft 22 for sharpening or replacement requires only that the cap 26 be removed, after which the disc 24 can be unseated. The other components of the cutter head 20 are also made so that replacement of the cutting disc 24 is made easy, as will be seen.

As best seen in FIGS. 2-4, the cutter head 20 comprises a generally circular central member 30 having opposite flat surfaces and provided with a central opening 32 to rotatably accommodate the cap 26 and the end of the drive shaft 22. The member 30 is made in two halves, being split along a line 33, as best seen in FIG. 4. In addition, a radially oriented, circular channel or slot 34 is provided centrally of the central member 30, the slot 34 opening into the central opening 32 and rotatably receiving the periphery of the cutter disc 24.

The central member 30 is formed with a generally horizontally oriented material receiving slot 36 which is open forwardly and extends rearwardly to a point just rearwardly of the center of rotation of the shaft 22, at which point the slot 36 is closed. The slot 36 thus defines spaced apart upper and lower jaws 38 and 40 between which is received the material to be cut. The lower jaw 40 includes a downwardly and forwardly extending guide shoe portion 42 which terminates in a smoothly rounded extremity adapted to engage and slip beneath the soft wrappings to be cut, traveling beneath the wrappings and raising them along the inclined surface of the guide shoe portion 42 for passage between the upper and lower jaws 38 and 40 to the area of the cutter disc 24.

The upper jaw 38 is also formed by depending cheek portions 44 and 46 located on opposite sides of the cutter disc 24 in fixed, spaced apart relation. The cheek portions 44 and 46 are formed as the lower extremities or depending portions of a pair of generally circular side plates 48 and 50 which are secured to the opposite faces of the central cutter head member 30 by a plurality of machine bolts 52 arranged about the periphery thereof. In addition, the side plate 50 is secured to the flange of the collar 18 by a plurality of machine bolts 54. With this arrangement, removal of the bolts 52 allows the side plate 48, the lower half of the central member 30, and the cap 26 to be removed, enabling replacement of the cutter disc 24.

As best seen in FIGS. 1, 3 and 4, the depending cheek portions 44 and 46 define side passages 56 and 58 on opposite sides of the cutter disc 24. In addition, the cheek portions 44 and 46 extend forwardly of the cutter disc 24 in overlying relation to the lower jaw 40, and particularly the guide shoe portion 42 thereof, to define a frontal passage 60. The passage 60 is located ahead of the cutter disc 24 and extends rearwardly into communication with the side passages 56 and 58.

The width or size of the openings to the side passages 56 and 58 is made sufficiently large to permit a sheet of deformable material to pass therethrough for cutting by the cutter disc 24, but the passages are made sufficiently small that a person cannot press his finger into contact with the cutter disc 24. The frontal passage 60 is similarly dimensioned to prevent a person from inserting his finger through the frontal passage 60. In addition, the generally inverted U-shape defined by the passages 56 and 58, as best seen in FIG. 3, provides an offset entry which makes it even less possible for a person to get his fingers caught in the cutter disc 24.

The fixed or non-pivotable nature of the structure surrounding the cutting area insures that nothing can be pivoted, pressed, or moved out of the way to expose the cutting disc 24.

In operation, the operator or user grasps the handle portion and moves the cutter head in a direction at right angles or transversely of the longitudinal axis of the handle portion 10. The guide shoe portion 42 slips beneath the sheet of deformable material to be cut, guiding it upwardly and rearwardly toward the cutter disc 24. The material is deformed into a generally inverted U-shape to pass through the passages 56, 58, and 60. After the material is severed by the cutting disc 24, the cut portions of the material pass outwardly thereof on either side of the rearward terminus of the slot 36.

An alternative embodiment of the power cutter is illustrated in FIG. 6, the showing being largely diagrammatic. This embodiment is adapted to effect a cutting action upon deformable material by moving the cutter along a path aligned with the longitudinal axis of the handle portion 10a. The cutter operates in a manner substantially identical to that of the power cutter previously described except that the electric motor in the handle 10a is coupled to the cutter disc 24 by means of a right angle drive. The right angle drive may be of any suitable type but preferably takes the form of a pair of bevel gears (not shown), one of which is mounted to the shaft on which the cutter disc 24 is carried, and one of which is mounted to the end of the drive shaft (not shown) which is connected to the electric motor. As will be apparent, rotation of the drive shaft is transmitted to the cutter disc 24 by meshing of the pair of bevel gears. With this arrangement the upper jaw 38a and lower jaw 40a can be made an integral part of the handle portion 100, except that suitable parting lines are provided for separation to enable replacement of the cutter disc 24, as will be apparent. However, the embodiment is primarily illustrative of a power cutter in which cutting occurs along a path aligned with the longitudinal axis of the handle portion. Although the power cutter of FIG. 6 is pushed to effect the cutting action, it will be apparent that the handle 10a could be reversely formed so as to extend in the opposite direction whereby the cutting action would be effected by pulling upon the handle portion.

Certain of the components of either embodiment of the power cutter of the present invention can be made of transparent plastic material to facilitate guidance of the cutter along a predetermined cutting path. This is particularly true of those components in the vicinity of the cutter disc 24.

In summary, the power cutter of the present invention is adapted to quickly and efficiently cut soft wrappings, and is constructed in such a way that the openings to the cutter disc are sufficiently small and so located that it is virtually impossible for a person to injure himself by catching his fingers or the like in the cutter disc 24.

Various modifications and changes may be made with regard to the foregoing detailed description without departing from the spirit of the invention.

I claim: 1. A power cutter for cutting deformable material, said cutter comprising:

circular cutter means; mounting means rotatably mounting said cutter means and including upper and lower jaws, said lower jaw having a forwardly extending guide shoe portion located generally below and extending forwardly of said cutter means, and adapted for passage beneath the material to be out, said upper jaw having fixed cheek portions extending downwardly on opposite sides of said cutter means in covering relation, and further extending forwardly of said cutter means in vertically and laterally spaced relation to said shoe portion to define passages ahead of and on opposite sides of said cutter means whereby material to be cut can be fed through said passages to said cutter means, the vertical and lateral spacing between said shoe and cheek portions being sufficiently narrow whereby entry of a persons finger into said passages is prevented; and

drive means coupled to said cutter means for rotating said cutter means at a speed sufficient to effect cutting of the material.

2. A power cutter according to claim I wherein said lower jaw includes a recess receiving the lower periphery of said cutter means.

3. A power cutter according to claim 1 and including elongated handle means secured to said mounting means and housing said drive means.

4. A power cutter according to claim 3 wherein said handle means is disposed generally parallel to the axis of rotation of said cutter means.

5. A power cutter according to claim 3 wherein said handle means is disposed generally perpendicular to the axis of rotation of said cutter means.

6. In a power cutter having cutter means and power means for rotating said cutter means to cut deformable material, cutter guard means comprising:

spaced apart upper and lower jaws, said lower jaw having a forwardly extending guide shoe portion for passage beneath the material to be cut, said upper jaw having depending cheek portions located on opposite sides of said cutter means in covering relation, said check portions being in fixed, spaced apart relation to said shoe portion to define side passages on opposite sides of said cutter means, said cheek portions extending forwardly of said cutter means in overlying relation to said lower jaw to define a frontal passage ahead of said cutting means and extending rearwardly into communication with said side passages, the width of the openings to said side passages and frontal passage being sufficiently large to permit the material to pass therethrough, and sufficiently small to prevent a person from pressing his finger therethrough into contact with said cutter means. 

1. A power cutter for cutting deformable material, said cutter comprising: circular cutter means; mounting means rotatably mounting said cutter means and including upper and lower jaws, said lower jaw having a forwardly extending guide shoe portion located generally below and extending forwardly of said cutter means, and adapted for passage beneath the material to be cut, said upper jaw having fixed cheek portions extending downwardly on opposite sides of said cutter means in covering relation, and further extending forwardly of said cutter means in vertically and laterally spaced relation to said shoe portion to define passages ahead of and on opposite sides of said cutter means whereby material to be cut can be fed through said passages to said cutter means, the vertical and lateral spacing between said shoe and cheek portions being sufficiently narrow whereby entry of a person''s finger into said passages is preveNted; and drive means coupled to said cutter means for rotating said cutter means at a speed sufficient to effect cutting of the material.
 2. A power cutter according to claim 1 wherein said lower jaw includes a recess receiving the lower periphery of said cutter means.
 3. A power cutter according to claim 1 and including elongated handle means secured to said mounting means and housing said drive means.
 4. A power cutter according to claim 3 wherein said handle means is disposed generally parallel to the axis of rotation of said cutter means.
 5. A power cutter according to claim 3 wherein said handle means is disposed generally perpendicular to the axis of rotation of said cutter means.
 6. In a power cutter having cutter means and power means for rotating said cutter means to cut deformable material, cutter guard means comprising: spaced apart upper and lower jaws, said lower jaw having a forwardly extending guide shoe portion for passage beneath the material to be cut, said upper jaw having depending cheek portions located on opposite sides of said cutter means in covering relation, said cheek portions being in fixed, spaced apart relation to said shoe portion to define side passages on opposite sides of said cutter means, said cheek portions extending forwardly of said cutter means in overlying relation to said lower jaw to define a frontal passage ahead of said cutting means and extending rearwardly into communication with said side passages, the width of the openings to said side passages and frontal passage being sufficiently large to permit the material to pass therethrough, and sufficiently small to prevent a person from pressing his finger therethrough into contact with said cutter means. 